Various water treatment methods for decreasing hardness of water are known and commercially employed. Detergents and other cleaning agents often contain numerous components to improve the cleaning activity of the detergent, including for example, components to counteract the effects of water hardness. Hard water is known to reduce cleaning efficacy both by forming films on surfaces and reacting with detergent and other cleaning components, making them less functional in the cleaning process. Various methods for counteracting and/or eliminating water hardness have been implemented by those skilled in the art, including for example, adding chelating agents or sequestrants into detersive compositions in amounts sufficient to handle the hardness ions and/or softening a water source via ion exchange. Ion exchange can be used to exchange hardness ions, such as calcium and magnesium, in the water with sodium or other ions associated with a resin bed in a water softening unit.
Various ion exchange methods are known by those skilled in the art. Most commonly, water is run through an exchange resin to adhere the hardness ions calcium and magnesium to a resin in the softener. However, when the resin becomes saturated it is necessary to regenerate the resin using large amounts of sodium chloride dissolved in water. This regeneration process has numerous known disadvantages, namely requiring the use of briny solutions and chloride from added sodium chloride used to flush out the resin. Accordingly, when water softeners regenerate they produce a waste stream that contains significant amounts of sodium, creating a burden on the system, e.g., sewer system, in which they are disposed of. The generated waste presents a multitude of downstream water re-use concerns, including for example water re-use applications like potable water usage and agriculture. Further, traditional water softeners add to the salt content in discharge surface waters, which has become an environmental issue in certain locations. These and other limitations of commercially-available water softening methods are described in further detail in U.S. patent application Ser. No. 12/764,621, entitled “Methods and Apparatus for Controlling Water Hardness,” the entire contents of which are hereby expressly incorporated herein by reference.
Accordingly, it is an objective of the claimed invention to develop improved methods and retrofitted systems for regenerating ion exchange resins for use in various institutional and industrial applications.
A further object of the invention is to develop a system and methods for using acid regenerate-able ion exchange resins to pre-treat water for the various institutional and industrial applications, resulting in the reduced demand for polymers and threshold reagents in cleaning compositions (e.g. detergents).
A further object of the invention is to improve ware wash and other cleaning application results through the application of softened acidic water generated by acid regenerate-able ion exchange resins at a point of use.
A still further object of the invention is to develop methods for applying protons in a treated water source to trigger events, such as regeneration of the resins, dispensing additional detergent and/or other cleaning aids, and the like.
Still further, the invention sets forth methods and systems for reducing scale build-up, spotting and/or film formation by treating a water source using an acid regenerate-able ion exchange resin.